Recently, an electronic device, e.g., a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit) are mounted on is proposed.
In such electronic device, a plurality of memory devices of the same specifications are mounted, one of the plurality of memory devices is used for, e.g., the CPU and the other of the plurality of memory devices is used for, e.g., the GPU.
Related references are as follows:    Japanese Laid-open Patent Publication No. 2000-40375;    Japanese Laid-open Patent Publication No. Hei 6-332797;    Japanese Laid-open Patent Publication No. 2000-30457; and    Japanese Laid-open Patent Publication No. 2004-118915.